So I am trying to get all the ps4 trophies for the faction missions and went back on on a old save to choose brother hood line,

I have done fires support, call to arms, semper invicta, shadow of steel, tour of duty, show no mercy, spoils of war. Nothing else is coming up on the main story line now. Do I have to get minute men to certain point now? I have taken castle with them and in process of getting settlements in the from ranks mission.

Any ideas?

I had this problem with the Railroad. Just continue the main story and you'll get the option to return to the BOS quest-line. Hope this helps